DEPARTMENT OF MARINE BIOLOGY. 191 



CO2 to the atmosphere. In general, however, the CO2 tension of the 

 surface waters of the Tropical Ocean is slightly higher than that of 

 the atmosphere, while in the cold seas the CO2 tension of the surface- 

 water is below that of the air. Thus the colder waters are receiving 

 CO2 from the atmosphere, while it is escaping from the sea over the 

 wide belt of the tropics. 



On September 10, 1919, a severe hurricane passed over Tortugas, 

 seriously damaging the wharf, the two main laboratory buildings, 

 and the machine shop, and throwing do^m the wndmill, as well as 

 destroying the cages which contained the cerions being experimented 

 upon by Dr. Bartsch. According to the U. S. Weather Bureau, the 

 barometer was 28.83 at Key West and 27.57 at Tortugas, these being 

 the lowest yet recorded from these regions. The damaged buildings 

 will be repaired as soon as is practicable. 



It is a pleasure to express the appreciation of the Department for 

 the kindness of the British Embassy in Washington in pro\'iding the 

 Director with a letter to the Governor of Fiji, and we are also indebted 

 to Hon. Josephus Daniels, Secretary of the U. S. Navy, for a letter 

 to the newly appointed governor of American Samoa, who was, how- 

 ever, our old friend Commander Warren Jay Terhune, who courteously 

 aided us in every way. We are also similarly indebted to the United 

 States Department of State for a letter to American consuls in the Pacific. 



Quarantine regulations incident to the epidemic of influenza and a 

 deficiency of steamers made it impossible to visit Fiji this summer, but 

 we intend to go there in 1920 in order to ascertain the growth-rate of 

 alcyonaria and corals planted out on the barrier reef off, Suva in August 

 1918, and to make a detailed study of various features of the reefs. 



Volumes ix and xii of Papers from the Department of Marine 

 Biology were published during the past year. These contain 620 

 pages and 124 plates. 



The following papers resulting from studies carried out under the 

 auspices of the Department of Marine Biology were published by 

 agencies other than the Carnegie Institution during the year : 



Harvey, E. N. 1918. Reversibility of the photogenic reaction in Cypridina. Jour. 



Gen. Physiol., vol. 1, pp. 13.3-14-5. 

 . 1919. Chemical natiu'e of Cypridina luciferin and Cypridina luciferase. Ibid., 



vol. 1, pp. 269-293. 

 Mayor, A. G. 1918. The grow'th-rate of Samoan coral-reefs. Proc. Nat. Acad. Sci., 



vol. 4, pp. 390-393. 

 . 1919. Detecting ocean currents by observing their hydrogen-ion concentration. 



Proc. Amer. Phil. Soc, vol. 58, pp. 1.50-160, 1 fig. 



